COMPARISON OF THE NEUTRONIC BEHAVIOR OF A PWR TYPE SMR CORE USING CERMET AND TRISO FUEL/COMPARACION EN EL DESEMPENO NEUTRONICO DEL NUCLEO DE UN SMR DE TIPO PWR USANDO COMBUSTIBLE CERMET Y TRISO

The use of non-conventional fuels in traditional Light Water Reactors (LWR) improves their performance in safety, as well as the characteristics of the fuel cycle. Using TRISO (Tristructural Isotropic) or SCF (Spherical Cermet Fuel) particles in a PWR-type (Pressurized Water Reactor) SMR (Small Modular Reactor) core enhances the proliferation resistance, fission products retention and greatly simplifies safeguards oversight. It has been shown that using TRISO fuel at low coolant temperatures can cause swelling induced by irradiation in the SiC barrier, so the use of another type of fuel without this issue and with equivalent neutronic performance to that obtained when TRISO fuel is used, may be more suitable for use in these types of plants. This work compares the neutronic performance of a PWR-type SMR core, using SCF particles with the same core using TRISO fuel in terms of burnup, spectrum, and radial power distributions. TRISO fuel has better multiplicative properties than SCF particles. Using SCF particles, the cycle duration decreases by approximately 8%, a difference that is lower when the fuel mass is increased. The differences in the spectrum are higher in the thermal zone. The radial power distributions at the beginning of the cycle and at the end of the cycle are similar. Pu-239 production is higher when TRISO fuel is used.